SSPC Transient Voltage Dissipation via Clamping Diodes
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Solution Overview
Problem
Conventional solid-state power controllers in electrical systems, such as aircraft systems, are inadequate in managing voltage transients, particularly during extreme events like lightning strikes, which can damage power MOSFETs due to insufficient transient voltage dissipation.
Innovation Solution
The implementation of a solid-state power controller (SSPC) system with multiple channels, each equipped with disconnect and enable switches, and voltage clamping diodes that allow for balanced dissipation of transient voltages through parallel channels, using diodes with different breakdown voltages to manage and dissipate voltage transients effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solid-state power controllers are used, then the system can operate with standard protection measures, but the power MOSFETs are vulnerable to damage from voltage transients exceeding their voltage rating
Solution Approach 1:
The patent introduces an intermediary voltage clamping device connected between the gate and source of the power MOSFET. This clamping device acts as a mediator that activates during voltage transients to limit the voltage across the MOSFET, preventing damage while allowing normal operation. The clamping voltage is set below the MOSFET's breakdown voltage to provide protective action before damage occurs.
2Reliability
If voltage clamping devices are added to protect power MOSFETs, then transient voltage protection is improved, but the device complexity and cost increase
Solution Approach 1:
The patent combines the voltage clamping function with the existing gate drive circuitry by connecting the clamping device between the gate and source terminals. This integration approach merges the protection function into the existing controller structure rather than adding completely separate protection circuitry, thereby reducing overall complexity while maintaining effective transient voltage dissipation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables balanced and efficient dissipation of transient voltages across multiple channels, minimizing stress on individual components and preventing damage from voltage transients, thereby enhancing the reliability of electrical systems during transient events.
Implementation Method 1
A voltage clamping diode is connected across the gate of the enable switch and is arranged to close the enable switch when a transient voltage applied to the SSPC channel exceeds the breakdown voltage of the voltage clamping diode
Data Source
AI summary
A solid-state power controller (SSPC) includes two or more SSPC channels for connecting a load to a feed bus. The SSPC channels include a disconnect switch and an enable switch having a terminal connected to a gate of the disconnect switch. A voltage clamping diode of the SSPC channel is connected to the gate of the enable switch, and is arranged to close the enable switch when a transient voltage applied to the SSPC channel when the transient voltage exceeds the breakdown voltage of the voltage clamping diode.